YOU SAID:

He has read his read messages while reading his readings

INTO JAPANESE

彼は読み上げメッセージを読みながら読んだ

BACK INTO ENGLISH

He read the reading message while reading it.

INTO JAPANESE

彼はそれを読みながら読みメッセージを読んだ。

BACK INTO ENGLISH

He read it and read the message.

INTO JAPANESE

彼はそれを読んでメッセージを読んだ。

BACK INTO ENGLISH

He read it and read the message.